This invention relates to a manufacturing method for synthetic leather, particularly to injecting and mixing several kinds of materials to produce reaction and then pouring on between two basic cloths for making a synthetic leather, not using solvent to pollute water and air, or enormous equipment used in a conventional manufacturing method.
A conventional manufacturing method for synthetic leather usually places various materials and solvent in one or several immersing tanks. Then basic cloth is guided to immerse in the materials in the tanks, subsequently the basic cloth is moved in a water tank to let its surface congeal, and then dried by means of an electric heating device to become a finished synthetic leather.
A large volume of solvent is used in the conventional manufacturing method for synthetic leather, potentially polluting heavily the environment. For example, wet-style synthetic leather uses dimethyl formamide (DMF) as solvent, which may be absorbed through human skin to the lungs to get poisoned. This chemical is listed in a toxic material table made by the Environment Protective Bureau. A factory is obligated to install equipment for collecting poisonous gas, water washing and treating waste gas according to the factory law, and all the factories and the government should record its control and management processes incessantly. Therefore, treatment of waste gas and wastewater need substantial time, work and expense, otherwise serious pollution may happen any time if carelessly controlled. In addition, the electric heating device used in the manufacturing process may use large electric power and work force for controlling.
Another kind of conventional dry-style synthetic leather is made by means of coating resin on a removable paper and dried, and then paste is coated on and adhered or with the movable paper and dried. It uses methyl ethyl ketone (MEK), which may cause acute toxipathic hepatitis, and another chemical, xylene, used in the manufacturing method is highly inflammable by heat, a spark or flame, causing a fire very easily, and polluting air and water as well. An electric drying device is also used, wasting large expense for electricity and managing force.
Moreover, manufacturing equipment used in the conventional manufacturing methods for synthetic leathers are impossible to make plastic foam treatment directly contained in the continual manufacturing processes.
The main objective of the invention is to offer a manufacturing method for a synthetic leather, not using any solvent, not needing a waste gas washing accommodation so that there is no pollution to air and water, saving expense for the accommodation, work force and electricity.
Another objective of the invention is to offer a manufacturing method for synthetic leather, including a foaming process used in case of need, directly connected with other manufacturing processes for continual treatment so as to manufacture synthetic leather with or without foam structure.